refactor(editor): use extension level config (#12110)

Closes: BS-3396

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Introduced structured and validated configuration options for database and linked document views, allowing for more flexible and reliable customization.
  - Enhanced view manager to conditionally enable AI-related paragraph placeholders and database/linked document extensions based on configuration.
- **Chores**
  - Updated dependencies to include the latest version of the Zod validation library.
  - Simplified and consolidated internal configuration and registration logic for AI and widget-related extensions.
- **Refactor**
  - Streamlined configuration types and removed unused or redundant configuration utilities to improve maintainability.
  - Improved robustness of linked widget configuration retrieval to handle optional service availability gracefully.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/widgets/linked-doc/package.json

@@ -28,7 +28,8 @@
     "fflate": "^0.8.2",
     "lit": "^3.2.0",
     "lodash-es": "^4.17.21",
-    "rxjs": "^7.8.1"
+    "rxjs": "^7.8.1",
+    "zod": "^3.23.8"
   },
   "exports": {
     ".": "./src/index.ts",